One man, two kernels, and a lot of RISC-V

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One man, two kernels, and a lot of RISC-V

A homebrew PC and mini-mainframe were only the warm-up for Yuri Zaporozhets' latest operating system

Liam Proven

Liam<br>Proven

Published<br>fri 26 Jun 2026 // 14:46 UTC

Yuri Zaporozhets of QRV Systems is a busy chap. He's built a new RISC-V-based personal computer, a mainframe on an FPGA, and rewritten QNX – twice.<br>Seemingly every month or two, The Reg FOSS desk gets an email telling us about some astonishing project that he has just got working. We're delighted to see that his most recent one, a new OS called QSOE, is winning some attention in the FOSS world at present.<br>But first, we thought we could tell a more complete story of how he got here by describing some of his previous projects.

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(By way of a disclaimer, we feel that we should say up front that he does use Anthropic's Claude LLM to help. To his credit, he does clearly state this.)

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GateMate Personal Computer<br>At the end of 2025, Zaporozhets wrote to tell us about his GateMate Personal Computer. The GateMate PC is something similar to a fairly high-end late-1980s IBM PC-compatible, but instead of a 286 or 386 CPU, it has a 25 MHz RISC-V core.<br>He told us the main inspiration for the GateMate PC: "The very first computer I saw in my life: an IBM PS/2 Model 30, in 1992. It also started in text mode." We worked on a few of those, and they were not great machines. The GateMate machine should easily outperform the later, faster Model 30-286. He also acknowledges another project: "the NeoRV32 softCPU by Stefan Nolting is great."<br>It has a VGA port that can output 80x30-character text in what back then we used to call Hi-Color, 8 KB of ROM containing a BIOS, and – although it's still in the early stages – its own OS, which he calls GMDOS. The characters are double-byte ones using UCS-2 Unicode.

The GateMate gets its name from the host hardware because the design is mostly software: it's implemented on an inexpensive FPGA board, the €50 Olimex GateMate A1-EVB (that's about £42 or $57). Its video controller is an original design, and he has added extra RAM: the machine has 8 MB of additional PSRAM on two chips, via a QSPI interface.<br>He blogged about the project, from receiving the board last August to getting a PLL working, to getting video out of it.<br>The Olimex GateMate board can do a lot more, though – which leads us to his next project.<br>GateMate System/359

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Also implemented on the same FPGA board is Zaporozhets' miniature mainframe, the System/359. This isn't a clone of the IBM System/360 mainframe series, the machines that introduced the idea of different computers being software compatible – it’s more of a tribute to it. For starters, the S/359 is a little-endian machine, while the S/390 is big-endian.<br>So it's not binary-compatible with the mainframe architecture, but it's similar. He started the project in January, and later that month, writing about its assembler, said: "GMS/359 keeps what's beautiful about S/360 – the channel I/O model, the clean instruction formats, the PSW concept – while quietly modernizing the rest. Little-endian bytes. Opcode-first encoding. PC-relative addressing. No more base register juggling. The '/359' isn't a typo. It's a declaration: inspired by, not compatible with."<br>Zaporozhets told The Register: "There is a working assembler with the POWERFUL macroprocessor – from NASM. I was a NASM contributor from 1999 to 2004 and maintained its RDOFF2 part. Now RDOFF2 is removed from NASM 3.0, but it continues to live in my asm359 project.<br>"Currently the processor can execute the simple IPL; channel I/O controller works (PS/2 kbd, UART, SYSINFO, even crypto processor (!)). Once I finish the PSRAM module, I will start working with SYS1.NUCLEUS."<br>So we can take it that as well as RISC-V and FPGAs, he has some familiarity with low-level systems design. His next project was with an OS that a lot of folks admire: QNX.<br>Porting QNX 6.4 to RISC-V<br>Although Zaporozhets wrote to us about this back in March, he also went public with it in a Reddit post: QNX 6.4 kernel ported to RISC-V; petition to BlackBerry to relicense old QNX sources under Apache 2.0.<br>QNX has an on-again-off-again relationship with FOSS. QNX has been around since the 1980s, as we reported when the company made QNX 8 non-commercial freeware in 2024. In that article, we mentioned that QNX published the source code of an earlier version back in 2007. Back then, QNX was self-hosting and had its own desktop environment – we showed a screenshot of its Neutrino GUI in our roundup of non-Linux PC OSes back in 2013, and GUIdebook has a whole screenshot gallery.

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The next year, that QNX 6.4 source code was mirrored from SourceForge over to GitHub, and it's still there. Zaporozhets took this long-obsolete codebase and ported it to RISC-V, targeting his own FU740 "workstation." It's not the whole OS, just "the kernel, the...